Google tells some Glass Explorers to invite a friend

Mountain View's kept itself as the gatekeeper for Google Glass, with developer signups at I/O and a social media contest, but now it's letting some users spread the wearable computing love. Google+ is lighting up with reports that Glass Explorers are receiving emails from Page and Co. allowing them to invite a friend to snag a device by becoming part of the program. In order to be eligible, invitees must be at least 18 years of age, a US resident and willing to pick up the hardware in San Francisco, New York or Los Angeles. Google's told us that a "small subset of Explorers" have received the message in its continuing effort to expanding the affair.